ORDER IV 



TELOTREMATA 



327 



Juvavella, Bittner. Small, smooth, biconvex shells, with a very short 

 CentronellaAike loop. Alpine Trias. 



Nucleatula, Bittner. Like Juvavella, but having a longer loop with a well- 

 developed and fimbriated vertical median plate. Alpine Trias. 



Dirutrella, Bittner. Alpine Trias. Chascothyris, Holzapfel. Devonian; 

 Germany. 



Family 2. Terebratulidae. Gray. 



Terebratulas developing originally a Centronella-liJce loop, and thence by a short 

 series of metamorphoses resulting at maturity in a free loop of varying form. 

 Devonian to Kecent. 



STRINGOCEPHALINAE. Dall. 



Sub-Family A. 



Terebratulidae with a long loop, foil 

 recurved in front. Probably no median coiled arm. 



margin of the dorsal 



not 



FIG. 548. 



Stringoctphalus Burtini, Defr. Devonian; Paffratli, near Cologne. A, Side-view, % natural size. J3, Greatly 

 reduced diagram showing hraohidium and median septa. C, Young specimen with large delthyrium and deltidial 

 plates. D, Interior of dorsal valve, natural size, partly restored (a, Adductors ; c, Crura ; d, Dental sockets ; 

 I, Loop ; pr, Cardinal process ; s, Median septum). 



Stringocephalus, Defr. (Fig. 548). Devonian ; Europe and North America. 



Sub-Family B. MEGALANTERINAE. Waagen. 



Terel/ratulidae with a long loop giving off ascending branches. Devonian to 

 Carboniferous. 



Megalanteris, Oehlert (Meganteris, Suess). Large, smooth, equally biconvex, 

 sub-oval shells, with the long convergent jugal processes of the loop extending 

 beyond the connecting band of the ascending branches. Devonian ; Europe 

 and North America. 



Cryptonella, Hall. Elongate oval shells with short jugal processes. 

 Devonian to Lower Carboniferous ; North America, England, and Bohemia. 



